Preliminary characterisation of Bacillus subtilis strain use as a dietary probiotic bio-additive in weaning piglet

Abstract

The aim of the study was to characterize the Bacillus subtilis ATCC 6051a strain, in order to establish its probiotic utility in piglet nutrition. The strain was assayed morphologically, culturally, biochemically, for hemolytic activity and enzymatically (amylase and protease). The identification and analysis of the biochemical characteristics was performed by catalase assay, API 50 CHB Biomerieux strips, apiweb API 50 CHB V 4.0 soft (B. subtilis very good identification, 99.4% ID) and ABIS online. The hemolytic activity was assayed on blood agar medium. The growth activity of strain was evaluated in two ways: static incubation (30 C, 24 h, 1.36 x 10 8 CFU/ml) and under constant agitation (30 C, 24 h, 150 rpm, (1.6 x 10 9 CFU/ml). The strain is a Gram-positive and rodshaped bacteria, arranged in short chains or in small irregular pairs with ability to produce spores on nutrient medium. The endospores were central, paracentral and subterminal, which did not deform the vegetative cell. The strain growth was aerobic and was nonhemolytic. The enzymatic process was observed by appearance of distinct zones around strain colonies. In conclusion, the results suggested that the strain present probiotic traits and can be further assessed for other probiotic characters (resistance to pH 2.0, resistance to bile acids and salts, antibacterial activity, induction of local immune response etc.).

Characterization ofBacillusspp. isolated from intestine ofLabeo rohita—Towards identifying novel probiotics for aquaculture

“…The strains studied in the present study were found to be non‐haemolytic. Non‐haemolytic strains of B. subtilis and B. licheniformis with probiotic potential have also been reported (Dumitru et al., 2018; Ghosh et al., 2020; Niu et al., 2019).…”

Effect of Bacillus subtilis on growth performance, bone mineralization, and bacterial population of broilers fed with different protein sources

“…The selection criteria of BS strain was based on the probiotic properties including growth rate, identification, and characterization of capacity to ferment carbohydrate substrates (API 50 CHB), amylase and protease production, survivability in low pH, bile salts, the growth rate of spores, hemolysis production, and susceptibility to antibiotics were assessed in vitro (data not shown). The bacterial strain was grown in a nutrient medium (g/L: tryptone 10; meat extract 5; sodium chloride 5; pH medium 7.2 ± 2 before autoclaving) and incubated in a shaker-incubator (200 rpm) at 37°C for 24 h in aerobic conditions as reported previously by Dumitru et al. (2018 , 2019) .…”

“…Coliforms were cultured on MacConkey agar (Oxoid CM0007) incubated aerobically at 37°C for 24 h as red, specifically colonies. E. coli biotype β-hemolytic was analyzed, as reported by Dumitru et al. (2018) .…”

Evaluation of Non-Encapsulated and Microencapsulated Lactic Acid Bacteria

“…Based on phenotypical identification, some characteristics from some identified strains (IBNA 29,33,41,48,50,51,56,57,61) are reported in other studies [32,33].…”

“…Blood agar plates [Trypticase soy agar (TSA, Sanimed) containing 5% (w/v) sheep blood] were used to test hemolysis activity. Interpretation was followed after incubation at 37 • C, for 24 h [29].…”